If you implement a temperature-calibration curve by analog means, it will drift in time, unless you use very high-quality and expensive components.

Calibrations done with a microcontroller have replaced those done with analog components in most applications, because the total cost is reduced in this way.

Even a relatively powerful 32-bit ARM microcontroller costs a fraction of a dollar. Good analog components, with guaranteed behavior in temperature and in time, are usually more expensive than microcontrollers.